This invention relates generally to a connector used for connecting wire harnesses of an automobile, and more particularly to a device for preventing an incomplete locking connection between a pair of connectors.
Generally, a connector comprises female and male connector housings, and by fittingly connecting them together, metal terminals provided therein are electrically connected together. In order to prevent the connected condition from being loosened by vibrations and so on when the connector is used in an automobile or the like, a lock arm is provided on one of the female and male connector housings, and an engaging hole is provided in the other, and they are engaged with each other to achieve the locking.
FIG. 1 shows such connector. In FIG. 1, reference character a denotes a male connector housing, and reference character b denotes a male connector housing. A flexible lock arm c of the cantilever type is formed on an upper surface of the male connector housing, and extends rearwardly. The female connector housing b has an engaging hole d for receiving a retaining portion cl of the flexible lock arm c.
In the above construction, when the male and female connector housings a and b are to be connected together, the retaining portion c1 is abutted against a front end of an engaging frame portion d1 of the female connector housing b, so that the flexible lock arm c is displaced downward (FIG. 2A), and then the flexible lock arm c is restored to its initial condition upon reception of the retaining portion c1 in the engaging hole d, thereby achieving a completely-connected condition (FIG. 2B) in which the locking connection is completed.
In the above locking connection between the male and female connector housings a and b, the flexible lock arm c in a displaced condition is strongly pressed against the engaging frame portion d1, and therefore the incompletely-connected condition (FIG. 2A) is often mistaken for the completely-connected condition. Moreover, if an electrical contact between metal terminals is made, the incompletely-connected condition can not be found even at an inspection step, and the product would be sent to the market. In such case, the connected condition would be loosened by vibrations and so on, and the electrical connection between the terminals would also be released later.
To overcome such difficulty, Japanese Utility Model Examined Publication No. Sho. 59-29351 proposes a lock mechanism shown in FIG. 3.
In FIG. 3, reference character M denotes a male housing, and reference character F denotes its mating housing, that is, a female housing. A lock arm G is formed on an upper wall e of the male housing M through an upstanding proximal portion f, and extends toward the mating female housing F. The lock arm g is flexible, and is resiliently displaceable upward and downward about the proximal portion f serving as a fulcrum. The lock arm g has a lock pawl h at its distal end. Reference character i denotes a receiving chamber for receiving a metal terminal (not shown).
The front half portion of the female housing F defines a sleeve portion J for receiving the male housing M, and a fitting chamber k for allowing the insertion of the lock arm g thereinto is provided in continuous relation to the sleeve portion j. A retaining hole 1 is formed through the upper wall of this fitting chamber. Although not shown, metal terminal receiving chambers corresponding to the receiving chambers i are provided in the rear half portion of the female housing F.
A lock release prevention piece m is inserted between the lock arm g in its locked condition and the upper wall e of the housing so as to provide confirmation of the completely fitting between the female and male housings F and M and also to prevent the release of the locking.
In the above construction, the female and male housings F and M are fitted relative to each other, and the lock pawl h is introduced into the fitting chamber k. When the fitting further proceeds, in the completely fitted position, the lock arm g is resiliently restored, and the lock pawl h on the upper surface thereof at the distal end thereof is engaged in the retaining hole 1, so that the female and male housings F and M are locked together completely.
Thereafter, the lock release prevention piece m is introduced between the proximal portion f of the lock arm g and an inlet surface k1 of the fitting chamber k from the side, and if this is done, the complete fitting is confirmed. Namely, if the female and male housings F and M are not completely fitted relative to each other, the lock release prevention piece m can not be attached, and therefore an incomplete fitting can be prevented.
In the above construction, however, in order to prevent the incomplete fitting between the female and male housings F and M, there are required two operations, that is, the direct fitting of the male housing M into the female housing F and the attachment of the lock release prevention piece m. And besides, even if the attachment of the lock release prevention piece m is forgotten, the electrical conduction is obtained as described above, and therefore there is a possibility that the check with the incomplete fitting is inadvertently forgotten. Moreover, since the lock release prevention piece m need to remain attached, the additional part is needed, and other problems are also encountered.